3D nanostructured N-doped $TiO_2$ with enhanced visible-light absorption for photocatalytic application

Abstract

Titanium dioxide is biochemically, chemically stable and non-toxic, common material and has a band gap of about 3.2 eV. Due to these unique characteristics, titanium dioxide is used for various purposes such as energy harvesting and pollutant purification. Among them, titanium dioxide has attracted attention as an active photocatalyst in ultraviolet wavelength band. However, due to the relatively large band gap of 3.2 eV, there is a disadvantage that it is active only in ultraviolet rays having high energy, and studies are being carried out to increase the surface area for higher efficiency. Previous studies have been carried out to increase the efficiency by increasing the surface area through nanoparticle type or nanowire type structuring, or to add metal elements or add non-metal elements to reduce the band gap. In this thesis, in order to increase the efficiency of the photocatalyst, two strategies mentioned above are both used. By using proximity-field nanopatterning, we could make titanium dioxide with three-dimensionally aligned monolith. And by oxidation of titanium nitride, nitrogen-doping was done. Therefore, we could increasing the surface area and reducing the band gap, making photocatalyst with high efficiency that can absorb light in visible light region.